1. Field of the Invention
The invention relates to systems and methods for treating excess wastewater from a sewer system, such as a combined sewer system or a sanitary sewer system.
2. Background Art
A combined sewer system is a sewer system that is designed to carry both sanitary sewage and storm water runoff. Such sanitary sewage and/or storm water runoff may be referred to as wastewater. During normal conditions, such as dry weather conditions, wastewater is transported by the combined sewer system to a wastewater treatment facility, where the wastewater is treated prior to being discharged. During a rain event, however, flow of wastewater may exceed treatment capacity of the treatment facility. In such a case, overflow wastewater may be diverted to one or more storage basins or tunnels until the treatment facility is able to treat the excess wastewater.
A method according to the invention for treating excess wastewater from a sewer system includes receiving the excess wastewater from the sewer system in a first portion of a container, wherein the container further includes a second portion in fluid communication with the first portion; allowing the wastewater to flow generally in a first direction through the first portion and then generally in a second direction through the second portion, wherein the second direction is different than the first direction; injecting a treating agent into the wastewater so as to treat the wastewater; and allowing a portion of the wastewater to flow from the second portion to an effluent passage in fluid communication with the second portion after the step of injecting a treating agent.
Further under the invention, a method for treating excess wastewater from a sewer system includes receiving the excess wastewater from the sewer system in a first portion of a shaft structure; allowing a first quantity of the wastewater to flow from the first portion of the shaft structure into a tunnel in inhibitable fluid communication with the shaft structure; allowing a second quantity of the wastewater to flow from the first portion of the shaft structure into a second portion of the shaft structure when flow into the tunnel is inhibited; injecting a treating agent into the second quantity of wastewater so as to treat the second quantity of wastewater; and allowing a portion of the second quantity of wastewater to flow from the second portion of the shaft structure to an effluent passage in fluid communication with the second portion of the shaft structure after the step of injecting a treating agent.
A wastewater treatment system according to the invention for treating excess wastewater from a sewer system includes a shaft structure adapted to receive excess wastewater from the sewer system. The shaft structure has first and second portions, and the first portion is in fluid communication with a tunnel. The system further includes a treating agent dispenser for introducing a treating agent into the excess wastewater, and an effluent passage in fluid communication with the second portion. During a sufficient rain event, excess wastewater flows from the sewer system into the first portion of the shaft structure and then into the tunnel. The treating agent dispenser is operative to introduce the treating agent to thereby treat at least a portion of the excess wastewater, such that if flow of excess wastewater to the shaft structure continues at a sufficient flow rate and flow into the tunnel is inhibited, treated excess wastewater will flow from the first portion into the second portion and then into the effluent passage.